Operating instructions

14. Replacing the batteries

a) ‘FHT80B-3’ heating control

If the symbol ‘ ’ appears on the LCD, this means that the batteries are low and must be

replaced.

To replace the batteries, proceed as follows:

• Remove the heating control from the wall holder and open the battery compartment cover

(slide down).

• Remove the batteries from the battery compartment and dispose of them according to the

applicable envronmental regulations. See section 18.

• Insert two new Mignon/AA batteries; make sure the polarity is correct. If possible, use high-

grade alkaline batteries.

• Close the battery compartment.

• If a ‘FHZ1000’ central unit is present, the heating control automatically requests the current

time and date and then sets these. Otherwise you need to set these manually.

The time program settings, the comfort/lowering temperature settings and so on are

maintained.

• As the heating control and the valve operating mechanism are no longer synchronised with each

other, the heating control performs a synchronisation procedure (‘

SynC AutoSynC Auto

SynC Auto’) that lasts

approx. 2 minutes. After this synchronisation the heating control returns to the normal operating

mode.

b) ‘FHT8V’ valve operating mechanism

The battery symbol appears when the valve operating mechanism’s batteries are low. In

addition, an acoustic signal is generated every 2 minutes for one hour, three times a day.

To replace the batteries, proceed as follows:

• Remove the battery compartment cover from the valve operating mechanism by sliding it

down.

• Remove the old batteries and dispose of them according to the applicable environmental

regulations. See section 18.

• Wait until all the segments of the valve operating mechanism’s LCD have gone out. You can speed

up this process by keeping the button on the valve operating mechanism pressed.